nostrum (n.)

c. 1600, "a medicine made of secret ingredients by secret methods," but commonly "quack medicine," from Latin nostrum remedium "our remedy" (or some similar phrase), presumably indicating "prepared by the person offering it," from Latin nostrum, neuter of noster "our," from nos "we," from PIE *nes- (2); see us. In extended use, "a pet scheme for accomplishing something" (1749).